What type of organism causes Alveolar Echinococcosis?

The organism that causes Alveolar Echinococcosis is a microscopic tapeworm, specifically Echinococcus multilocularis. This parasitic tapeworm typically infects canids, such as foxes and dogs, which serve as definitive hosts. When humans accidentally ingest the eggs of the tapeworm, usually via contaminated food or soil, the larvae can develop in the liver and cause severe health issues, including the formation of cysts.

Understanding the nature of the organism is crucial, as it highlights the lifecycle of the parasite and its interaction with both hosts and the environment. This knowledge is important for prevention and control measures, especially in areas where the disease is endemic. Each of the other options represents different classes of organisms that do not relate to Alveolar Echinococcosis; therefore, they do not have the capability to cause this specific disease.